1. Field of the Invention
The invention relates to a facing for rollers, in particular vibratory rollers, for the purpose of ground compaction.
2. Description of the Related Art
In comparison with the frequently encountered, known roller facings which have a cylindrical lateral surface and have poor ground traction specifically on upward slopes, but also in the case of unfavorable ground conditions, and tend to slip in these aggravated operating conditions, facings as described herein have the advantage of more reliable traction in these aggravated conditions.
In the case of the known facings of this type, which up until now have only been used for static rollers, the lateral surface is made up of rectangular lateral-surface sections, of which the long side edges extend parallel to the axis of rotation of the facing. Although this form of lateral surface effects the more reliable traction desired, because the bending lines, which extend over the facing width and are located between the planar surface sections, dig into the ground again and again, the increased traction lasts only for the duration of the engagement of such a bending line in the ground, whereas there is an increased risk of slippage when the planar rectangular surface section, which follows an engaging bending line in each case, rests flat on the ground. For this reason, facings which are formed from rectangular surface sections are not suitable either for use in conjunction with a vibratory roller in the case of which the facings are made to vibrate by a vibrator unit which produces a circular vibration or a directed vibration.
The known facings with a lateral surface formed from rectangular planar sections also have the disadvantage of extremely jerky operation, the non-uniformity being all the greater the smaller the number of rectangles used to make up the lateral surface.
In order to improve the traction, the prior art has also proposed to provide the facing surface with grouser bars. Apart from frequently undesirable excessive deformation on the surface of the ground which is to be compacted, grouser-bar facings have the great disadvantage that the material which is to be compacted can clog up between the grouser bars, and the grouser-bar facing is far more difficult to clean than a facing with a surface which is smooth or is made up of planar sections.
Taking the above-mentioned prior art as departure point, the object of the invention is to provide a facing which is also suitable, in particular, for use with vibratory rollers, which is distinguished by traction which is considerably better than that of cylindrical facings, and also than that of the known facings with the lateral surface formed from planar sections, and additionally by rotation which is considerably better than that of the last-mentioned known facings, and which is also very easy to clean.
The above object is achieved by providing a facing for rollers configured to compact ground. The facing includes a lateral surface that is formed from planar lateral-surface sections in the form of a triangle. Adjacent lateral-surface sections each include one triangle side having an equal length in common. The adjacent lateral-surface sections are arranged such that, in an alternating manner in the circumferential direction of the facing, a triangle vertex of a preceding lateral-surface section on the end sides of the facing is followed by a triangle side, located opposite a corresponding triangle vertex, of the following lateral-surface section.
Alternatively, the triangles can have a truncated end to form a trapezium such that the adjacent lateral-surface sections each include one trapezium side having an equal length in common. In this version of the lateral-surface sections, the adjacent lateral-surface sections are arranged such that in an alternating manner in the circumferential direction of the facing, on the end sides of the facing, a shorter trapezium side of a preceding lateral-surface section is followed by a longer trapezium side, located opposite a corresponding shorter trapezium side, of the following lateral-surface section.
The configuration of a facing according to the invention means that during operation of the facing, more or less in any angled position of the latter, at least part of the length of one of its angled bending lines extending over the facing width is in engagement with the ground and thus, even on upward slopes, ensures uninterrupted, essentially slippage-free traction. In comparison with the facings which are made up of rectangular lateral-surface sections, and in the case of which the individual surface-area sections strike the ground one after the other with a jerking movement, the seamless engagement in the ground of the successive facing bending lines between the planar lateral-surface sections also results in considerably more uniform and smooth rotation of the facing, and, in the case of vibrator units being used, the flat lateral-surface sections transmit the vibratory forces into the ground with particularly high efficiency. In this case, the surface-area load is similar to that in the case of vibration plates. Added to this is the fact that the high linear load at the abutment locations between the individual planar lateral-surface sections aids the compaction operation farther.
The planar triangular or trapezoidal lateral-surface sections are preferably shaped identically to one another and are each in the form of an isosceles triangle or trapezoid, in which case they adjoin one another by way of the legs of equal length.
A further preferred embodiment of the facing according to the invention consists in that a plurality of adjoining lateral-surface sections are produced from a common plate by bending the plate for which purpose bending using a laser beam is particularly suitable.
As is customary in the case of compaction rollers, it is also possible in the case of a roller having facings according to the invention for the facing to extend individually over the entire roller width or, in the case of the individual axles, for in each case a plurality of facings to be arranged one beside the other with aligned axes of rotation.
The invention is explained in more detail hereinbelow, with reference to the drawing, using exemplary embodiments.